| 摘要 |
PURPOSE:To dry an aq. mold coating material with good efficiency without generating a defective product owing to excessive heating by putting the casting mold and core to which the mold coating material is coated into an evacuated electromagnetic heating oven and irradiating electromagnetic waves thereon. CONSTITUTION:The electromagnetic waves are generated while an electromagnetic wave oscillator 1 is cooled by the water in a water tank 7 fed by a pump 6. The casting mold and core to which the aq. mold coating material is coated are put into the electromagnetic heating oven 2 evacuated to -300-700mmHg by a vacuum pump 5 and a vacuum tank 4 and the electromagnetic waves are irradiated thereon to dry the mold coating material. Since the mold and core are electromagnetically heated in the reduced pressure vessel, the b.p. of the water in the mold coating material decreases down to 70-75 deg.C. The lower drying temp. of the mold coating material is thus required and the collapse of the casting mold and core occuring in the combustion, decomposition, etc. of the binder in the mold and core owing to the excessive heating by the irradiation of the electromagnetic waves is obviated. The generation of the defective casting mold and core as a result of the defective drying is obviated and the drying efficiency is improve. |
